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Increasing biodiversity in agroecosystems decreases climate change problems

This content has been downloaded from IOPscience. Please scroll down to see the full text. 2009 IOP Conf. Ser.: Earth Environ. Sci. 6 372034 (http://iopscience.iop.org/1755-1315/6/37/372034) View the table of contents for this issue, or go to the journal homepage for more

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Climate Change: Global Risks, Challenges and Decisions IOP Conf. Series: Earth and Environmental Science 6 (2009) 372034

IOP Publishing doi:10.1088/1755-1307/6/7/372034

P37.27 Increasing biodiversity in agroecosystems decreases climate change problems H Nonato de Souza(1), EMG Duarte(2), MI Aguiar(3), Raphael BA Fernandes(2), E de Sá Mendonça(2), IM Cardoso(2) (1) Wageningen University and Research Center, Wageningen, The Netherlands (2) Federal University of Viçosa, Viçosa, Brazil (3) Federal University of Ceará, Fortaleza, Brazil Introduction: To mitigate the problems of climate change, taking into account biodiversity in agroecosystems, changes in the agricultural matrix are necessary, in order to produce in a more sustainable way. The Green Revolution types of technology, the base of the so- called modern agriculture, depends on non-renewable energy, mainly petroleum, and monoculture. These kinds of technologies cause several environmental and social problems. In the Zona da Mata of Minas Gerais, Atlantic Coastal Forest, Brazil, we have been working with agroecology, as a style of agriculture within an ecological framework. In agroecology the objective is to develop agroecosystems with minimal dependence on high agrochemical and energy inputs outside the area. Therefore, biodiversity and knowledge of the farmers are important. Monoculture does not combine with Agroecology. Material and Methods: Following the agroecological principles, the non-governmental organization, Center of Alternative Technology (CTA) in partnership with the Soil Science Department of the Federal University of Viçosa and small-farmers organizations developed agroforestry systems (in a participatory way). These systems are important for production diversification, carbon sequestration, agroclimate zone etc. In 1994, we started around 30 experiments on degraded lands and monoculture coffee with family farmers of several municipalities. From 2003 to 2005, CTA, farmers and the Soil Department systematized the experiences with the agroforestry systems, using a participatory approach. We estimated the biomass production of seven tree species used by the farmers in their agroforestry systems, based on the diameter at breast height (DBH). The temperature inside and outside the agroforestry systems was measured monthly during one year. Total soil carbon was measured at three depths in one full sun coffee, one agroforestry coffee and one forest, all neighbours. Results and discussion: Agroforestry systems diversified the production and increased the environmental service. More than 80 species of trees, most native, were found in the agroforestry systems, such as abacate (Persea americana, avocado), açoita-cavalo (Luehea grandiflora), eritrina (Erytrina verna), fedegoso (Senna macranthera), ingá (Inga subnuda), ipê-preto (Zeyheria montana), papagaio (Aegiphila sellowiana) and banana (Musa sp.). If we transform 50% of the coffee fields in the Zona da Mata (97.000 ha) in agroforestry coffee with 50 trees/ha (can be more) we will sequester around 115.000 ton C/year. According to the climate change predictions, in Brazil, the coffee crop can disappear or be restricted to some areas in the next 30 or 40 years, when the temperature raises around 3oC. The ideal temperature for arabica coffee ranges from 18 to 23oC. The average temperature in the Zona da Mata is 18oC. Hence, most of the region will be inappropriate for coffee cultivation with climate change, unless we use agroforestry systems; with the trees in the agroforestry systems the temperature can decrease with 3oC to 5oC. Soil carbon, a way to sequester carbon, increased at least 10% in agroforestry systems when compared to full sun coffee (Figure 1).

c 2009 IOP Publishing Ltd 

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Climate Change: Global Risks, Challenges and Decisions IOP Conf. Series: Earth and Environmental Science 6 (2009) 372034

IOP Publishing doi:10.1088/1755-1307/6/7/372034

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Carbono Orgânico Total (g kg ) 10 20 30 40

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SoilCamada depth (cm) (cm)

0 10 20 Forestry MSA

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Agroforestry SAFA Full sun CCA

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Figure 1: Total Soil Organic Carbon (g/kg), Zona da Mata of Minas Gerais, Brazil. Conclusion: The use of the biodiversity in agroforestry systems can help to mitigate the problems associated with climate change in the Zona da Mata and restore the native vegetation of the severely degraded Atlantic Coastal Rainforest. (Acknowledgements: FAPEMIG, CAPES and CNPq)

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